In general, a body of a heat-cooker such as a frying pan, a saucepan, or the like to which high-temperature heat is transmitted is manufactured using an iron and steel material, or an aluminum or stainless steel material. Various methods are researched and developed to improve the physical properties such as durability, heat resistance and the like of such a heat-cooker.
The applicant developed a ceramic coating composition for improving corrosion resistance, heat resistance and the like of an aluminum heat-cooker, and a patent relating to the ceramic coating composition has been granted registration. In addition, the applicant developed a heat-cooker coated with the ceramic coating composition, and a patent relating to a structure of a coating layer for the heat-cooker, which is disclosed in Korean Patent No. 10-765382 (registration date: Oct. 2, 2007), and a patent relating to a ceramic coated heat-cooker made of an iron and steel material and a manufacturing method thereof, which is disclosed in Korean Patent No. 10-0871877 (registration date: Nov. 27, 2008), have been granted registration. The heat-cookers of the above patent documents will be described hereinafter. As shown in FIG. 1, the heat-cooker made of an aluminum material, which is disclosed in Korean Patent No. 10-765382 (registration date: Oct. 2, 2007), is directed to a heat-cooker in which the outer surface of a body 1 made of an aluminum material of the coating layer structure for the heat-cooker is subjected to sandblastering to thereby form a corrugated pattern 2 thereon, the entire corrugated pattern 2 is subjected to anodizing (anodic oxidation) to thereby form an aluminum oxide film layer 3 thereon, and then a ceramic coating layer 4 is formed on the outer surface of the aluminum oxide film layer 3 so as to improve corrosion resistance, wear resistance, and the like. As shown in FIG. 2, the ceramic coated heat-cooker made of an iron and steel material, which is disclosed in Korean Patent No. 10-0871877 (registration date: Nov. 27, 2008), is directed to a heat-cooker in which corrugated patterns 2 and 2′ are formed on the top surface and the underside of a body 1 made of an iron and steel material, respectively, conversion coating layers 3 and 3′ are respectively formed on the underside and the top cooking surface of the corrugated patterns 2 and 2′, and then ceramic coating layers 4 and 4′ are formed on the outer surfaces of the conversion coating layers 3 and 3′.
The heat-cookers which were developed by the applicant and for which patents have been granted registration improve the physical properties such as corrosion resistance, wear resistance and the like, but encounter a problem in that the cooking surface of the ceramic coating layer frequently comes into close contact with a cooking utensil such as a spatula, a turner or the like while cooking foods in the long-term use of the heat-cookers to cause a damage to the ceramic coating layer, thereby leading to a deterioration in the chemical and mechanical properties such as corrosion resistance and wear resistance and thus an additional degradation in the non-stick characteristics.
Therefore, in an attempt to overcome the above problem, the applicant developed the ceramic coated heat-cooker made of an iron and steel material and the manufacturing method thereof, which is disclosed in Korean Patent No. 10-0871877 (registration date: Nov. 27, 2008), and a patent relating thereto has been granted registration. As shown in FIG. 3, the applicant developed an enameled heat-cooker having a non-stick ceramic coating layer, which is disclosed in Korean Patent No. 10-1104680 (registration date: Jan. 4, 2012) and in which lower and upper enamel layers 31 and 32 are formed on both surfaces of a body 10 made of an iron and steel material, respectively, and a non-stick ceramic coating layer 40 is formed on the upper enamel layer 32, and a patent relating thereto has been granted registration.
The enameled heat-cooker is significantly excellent in the chemical and mechanical properties such as corrosion resistance and wear resistance by virtue of the enamel layers and the ceramic coating layer, which are formed on the body of the enameled heat-cooker, but has a shortcoming in that the heat-cooker becomes heavyweight due to the enamel layers formed with a vitreous glaze, thus causing homemakers to suffer from an inconvenience in use.